Phenyl-indol-sulphonic acids



Patented July 12, 1932 UNITED STATES PATENT OFFICE EDUARD TSCHUNKUR, OF COLOGNE-MULI-IEIM, FRITZ BALLAUF, OF ELBERFELD, AND

ERNST HERDIECKERHOFF, OF OPLADEN, GERMANY, ASSIGNORS TO GENERAL ANI- LINE 'WORKS, INC., '61 NEW YORK, N. Y., A CORPORATION OF DELAWARE PHENYL-INDOL-SULPHONIC ACIDS No Drawing. Application filed August 29, 1930, Eerie No. 478,784, and Germany February 11, 1928.

The present invention relates to a process of preparing phenyl indol-sulphonic acids and to the new compounds obtainable thereby, more particularly it relates to compounds of the probable general formula:

wherein one y stands for a sulphonic acid group, the other ys stand for hydrogen, R stands for methyl or ethyl, and R stands for methyl, ethyl or a radical of the benzene series, but R and R not simultaneously standing for ethyl and a radical of the henzene series, or R and R jointly stand for the penta-methylene radical, the reaction proceeds with formation of the indole nucleus according to the following equation:

As condensing agents we mention by way of l 1 'd l 7 l h example zlnc cnlorl e anc a -90% su p uric acid; in using the first mentioned condensing agent we are working at temperatures be- 1 tween about 150-200 (1., while, when performing the condensation in sulphuric acid, we prefer to work at somewhat lower temperatures, say between 100 and 150 C., in order to avoid a simultaneous sulphonation.

The phenyl indol-sulphonic acids are isolated from the reaction mixtures in a manner more fully described in the examples.

The starting ketone hydrazone sulphonio acids of the general formula:

are obtainable in a convenient manner by heating at temperatures between about 50 and 100C. about equimolecular proportions of a water soluble salt, especially alkali metal salt, of a phenyl-hydrazine-o-, mor p-sulphonic acid and acetone, methyl-ethyl-ketone, diethyl-ketone, a Inethyl-phenyl-ketone or cyclohexanone in aqueous solution neutrally reacting to litmus.

The phenyl-indol-sulphonic acids prepared according to our process are generally colorless, crystalline substances, easiiy soluble in water in the form of their alkali metal salts and are valuable intermediate products in the manufacture of dyestuffs.

The invention is illustrated by the following examples, without being limited thereto:

EXAMPLE 1 kg. of hydrazone, prepared from o-phenyl-hydrazine-sulphonic acid and acetophenone, are molten together with kg. of zinc. chloride; the reaction is vigorous, and the temperature quickly rises to 200 G. Then the melt is poured into water and filtered off from the Q-phenylindol-7-sulphonic acid of the following formula:

From a common salt solution the sodium salt of this Q-phenylindol-7-sulphonic acid crystallizes in small sticks; the yield is almost quantitative. The product shows the indole re action with pine shavings.

EXAMPLE 2: 10 kg. of hydrazone from mphenylhydrazine-sulphonic acid and acetophenone are treated with kg. of zinc'chloride (as described in Example 1). The 2- phenylindol-6-sulphonic :acid of the following constitution is formed.

EXAMPLE 3: 10 kg. of hydrazone, obtainable from p-phenylhydrazine-sulphonic acid and acetophenone, are treated with 50 kg. of zinc chloride (as described in Example '1) thereby the 2-phenylindol-5-sulphonic acid of the following constitution is formed:

EXAMPLE 4: 10 kg. of hydrazone, prepared from .o-phenylhydrazine-sulphonic acid and p-met'hylacetophenone, are treated with 5.0 kg. of zinc chloride (as described in Example 1). The 2-(p-tolyl) indol-7-sulphonic acid of the following constitution is formed:

EXAMPLE 5: 10 .kg. of hydrazone, obtainable from m-phenylhydra-zine-sulphonic acid and p-methylacetophenone, are treated with -50 kgaof zinc chloride (as described in EX- ample 1.). The 2- (p-tolyl)indol-6-sulphonic -acid formed has the following-constitution:

o om o113 EXAMPLE .6; 10 kg. of vhydrazone, obtainable from p-phenylhydrazine-sulphonic acid and ,p-methylacetophenone, are treated with 50kg. of zinc chloride as described in EX- ample 1) The 2- (p-tolyl) .indol-5-sulphon- .ic acid .of .the following constitution is formed:

HOiS *n o-cuL-cizn EXAMPLE 7 10 kg. of ".hydrazone, obtainable from o-phenylhydrazine-sulphonic acid and p-chloroacetophenone, are treated with 50 kg. of zincohloride (as described in EX- ample 1). The 2-(p-ch lorophenyl) indol-7- sulphonic acid of the following constitution is formed:

EXAMPLE 8: 10 kg. of hydrazone, obtainable from m-phenylhydrazine-sulphonic acid and p-chloroacetophenone, are treated with 50 kg. of zinc chloride (as described in EXample 1). The 2-(p-chlorophenyl) indol-G-sulphonic acid of the following constitution is formed:

EXAMPLE 9:1.0 kg. of hydrazone, obtainable from p-phenylhydrazine-sulphonic acid and p-chloro-acetophenone, are treated with 50 kg. of zinc chloride (as described in EX- ample l). The 2-(p-chlorophenyl)sindol-5- 'sulphonic acid of the following constitution is formed EXAMPLE l0: 1 kg. of hydrazone, obtainable from m-phenylhydrazine-sulphonic acid and acetophenone, is slowly introduced into 5 kg. of'sulphuric acid (85%), and the soluing, the sodium salt of the Q-phenylindol-(t sulphonic acid crystallizes. The product is identical with that obtained in accordance with Example 2.

EXAMPLE 11: 10 kg. of hydrazone, obtainable from o-phenylhydrazine-sulphonic acid and acetone, are treated with 50 kg. of zinc chloride (as described in Example 1). The methyl-indol-7-sulphonic acid of the following constitution is formed:

SOiH

EXAMPLE 12: 10 kg. of hydrazone, obtaini i;

able from o-phenylhydrazine-sulphonic acid and diethylketone, are treated with 50 kg. of Zinc chloride (as described in Example 1).

The 2-ethyl-3-methylindol-7-sulphonic acid J of the following constitution is formed:

Q (H]OHa NH/ C-OzHs dOsH EXAMPLE 13: 10kg. of hydraz'one, obtain- .able from o-phenylhydrazine-sulphonic acid and cycloh'eXanone, are treated with 50 kg. of zinc chloride (as described in EXa-mple 1).

After recrystallization, the sodium salt of the 1-2-34-tetrahydrocarbazol-8sulphonic acid having the following formula:

se arates in beautiful crystals.

XAMPLE 14: 10 kg. of hydrazone, obtainable from m-phenylhydrazine-sulphonic acid and cyclohexanone, are treated with 50 kg. zinc chloride (as described in Example 1). The 1-2'34-tetrahydrocarbazole-7-sulphonic acid of the following constitution, is formed:

We claim:

1. The process which comprises condensing by means of an acid condensing agent a ketone hydrazone of the general formula:

wherein one 3 stands for a sulphonic acid group, the other ys stand for hydrogen, R stands for methyl or ethyl and R stands for methyl, ethyl, aradical of the benzene series, but R and R not simultaneously standing for ethyl and a radical of the benzene series, or R and R jointly stand for the pentamethylene radical in zinc chloride as condensing agent at a temperature of 150200 G.

3. The process which comprises heating a ketone hydrazone of the general formula:

in zinc chloride as condensing agent at a temperature of l50200 C.

4. The process which comprises heating a ketone hydrazone of the following formula:

in zinc chloride as condensing agent at a temperature of 200 C.

5. The process which comprises heating a ketone hydrazone of the general formula:

in zinc chloride as condensing agent at a temperature of 150-200 C.

6. The process which comprises heating a ketone hydrazone of the following formula:

in zincchloride as condensing agent at a temperature of 200 C.

7. The process which comprises heating a ketone hydrazone of the general formula:

in zinc chloride as condensing agent at a temperature of 150200 C.

8. The process which comprises heating a ketone hydrazone of the following formula:

11 ONHN=0 in zinc chloride as condensing agent at a temperature of 200 C.

9. As new products phenyl-indol-sulphonic acids of the probable general formula:

ll 11 /C-R wherein one y stands for a sulphonic acid group, the other y?s stand for hydrogen, R stands for methyl, ethyl or a radical of the benzene series, a: stands for hydrogen or methyl, but R and m not simultaneously representing a radical of the benzene series and methyl, being generally colorless crystalline substances, in the form of their alkali metal salts easily soluble in water and being valuable intermediate products in the manufacture of dyestuffs.

10. As new products phenyl-indol-sulphonic acids of the probable general formula:

wherein one 3 stands for a sulphonic acid group, the other ys stand for hydrogen and wherein R stands for a radical of the benzene series, being generally colorless crystalline substances, in the form of their alkali metal salts easily soluble in water and being valuable intermediate products in the manufacture of dyestuffs.

11. As a new product the phenyl-indol-sulphonic acid of the following formula:

o HOaS o being a colorless crystalline substance, in the form of its alkali metal salts easily soluble in water and being a Valuable intermediate product in the manufacture of dyestuffs.

12. As new products phenyl-indol-sulphonic acids of the probable general formula I HOaS H being a colorless crystalline substance, in the form of its alkali metal salts easily soluble in water and being a valuable intermediate product in the manufacture of dyestuffs.

14. As new products phenyl-indol-sulphonic acids of the probable general formula:

u N /CC2H5 wherein one 3 stands for a sulphonic acid group, the other ys stand for hydrogen, being generally colorless crystalline substances, in the form of their alkali metal salts easily soluble in Water and being valuable intermediate products in the manufacture of dyestufls.

15. As a new product the phenyl-indol-sulphonic acid of the following formula:

N GOzH& HOsS III I being a colorless crystalline substance, in the form of its alkali metal salts easily soluble in water and being a valuable intermediate product in the manufacture of dyestuffs.

In testimony whereof, we aflix our signatures.

EDUARD TSCHUNKUR. FRITZ BALLAUF. ERNST HERDIECKERHOFF. 

